we are talking about holy places of the three, main religions. >> reporter: it's so politically charged. >> so politically charged. >> reporter: discovered by accident in the 19th century, when an archaeologist was walking his dog. these caves and tunnels is known as solomon's quarry. king solomon is the founding father of the free masons. >> reporter: the reminder of solomon, his temple and his construction, seems to seep from these walls. tears of the king. >> the tears of the king. >> reporter: why is he crying? >> this was the end of the first temple period. >> reporter: it was under his rule that jerusalem fell to the babylonians. the temple was destroyed. and the arc of the covenant went missing from history and the pages of the bible. >> the last time anybody really sees it, according to the biblical tradition. >> reporter: many believe these underground tunnels were used to secretly transport the ark out of jerusalem. and when the babylonian troops took inventory of the treasures they plundered, something was missing. >> there are stories that maybe someone spirited the ark out